Method for projecting a thread under influence of a confined jet of a pressurized fluid



July 7, 1970 G. J. VERMEULEN 3,519,030 METHOD FOR PROJECTING A THREAD UNDER INFLUENCE OF A CONFINED JET OF A PRESSURIZED FLUID Filed Sept. 25, 1968 United States Patent 3,519,030 METHOD FOR PROJECTING A THREAD UNDER INFLUENCE OF A CONFINED JET OF A PRES- SURIZED FLUID Geert Jan Vermeulen, Beethovenlaan 34, Deurne, Netherlands Filed Sept. 25, 1968, Ser. No. 762,589 Claims priority, application Great Britain, Sept. 26, 1967, 43,870/ 67 Int. Cl. D03d 47/28 US. Cl. 139127 12 Claims ABSTRACT OF THE DISCLOSURE In this method the weight of a local portion of the thread is increased, and a high velocity driving jet of fluid is discharged in driving engagement with such thread portion. The discharging of the driving jet is continued during only a fraction of the time necessary for the thread to be displaced over its full length, and subsequently a separate flow of a supporting and transporting fluid is continued in contact with the thread during the remainder of the time necessary for displacing the thread over its full length.

BACKGROUND OF THE INVENTION The present invention relates to a method for projecting a thread under influence of a confined jet of a pressurized fluid. Moreover the invention relates to a device for carrying out the method according to the invention.

Such a method is particularly important in the textile industry where the need exists to project a thread in the shed of a loom in an automatic and quick manner.

Hitherto air has been used on a large scale as driving fluid for projecting a thread. Practically, however, several connected problems arise. 4

Experience namely shows that depending on the nature of the thread, certain threads can be transported by air more easily than another one. On natural fibres such as cotton the air appears to have sufficient grip; on the other hand the grip of air on synthetic fibres, 'being smooth by nature, is much less Whereas raw fibres may cause other difiiculties when being projected by air. In essence this phenomenon appears to be based upon a collision phenomenon which, depending on the nature of the fibre, is involved with more or less friction. Also a slip effect occurs and it could be ascertained that synthetic fibres have in this respect a lower coefiicient of friction due to their smoothness. Which of both effects will dominate depends to a large extent on how the driving jet is directed in respect of the thread.

Often the driving fluid is caused as a concentrated jet to skim along the thread so that if the thread were in the center of the jet, the interrelation between driving fluid and thread would be a matter of pure friction. Due to turbulent activities of the driving fluid at the speeds used in practice the stress falls notwithstanding on the collision effect, the friction effect being secondary. Other factors involved are the density of the medium and the relative velocity of the thread in respect of the medium.

In the weaving of threads the projecting velocity determines the velocity with which the weft threads can be introduced in the shed of a weaving loom. Demands made thereon are rapidly increasing. In conventional methods water or air jets are applied for projecting the thread in the shed of a weaving loom. While this method allows for a quick displacement of the thread in an economical manner, the use of air as driving fluid has the drawback that the consumption of air is enormous. In

addition the velocity obtainable is restricted due to the slow operation of the air valves, and the power required by a compressed air installation is so much that just for this reason it is desirable to look for cheaper means. A further increase of the relative velocity would require an increase of the pump power out of proportion so that the method would be no longer profitable. Further the risk of damaging the structure of the thread and therefore of a premature rupture is increased when working with such high speeds.

On the other hand water jets have the drawback that the fabric being manufactured with the aid of weft threads thus driven will be completely Wet.

SUMMARY OF THE INVENTION The method according to the invention eliminates these drawbacks in that only locally the thread is made heavier and the driving jet is confined to that heavier portion of the thread, the driving fluid as a whole being made operative during only a fraction of the time necessary for the thread to be displaced over its full length.

Owing to this measure the power needed for the driving fluid can be reduced considerably. As an additional advantage the heavier thread portion is more resistant against the mechanical force of the driving jet and the risk that the structure of the thread is disturbed, is lessened. The above principle can be elaborated in various ways. For example a thickening or other deformation of the proper material of the thread may be provided in the shape of a knot, a node, a loop or a wrinkle applied manually or mechanically for instance by local heating (in the case of natural fibres by sintering, in the case of artificial fibres by fusing) or by external forces. It is also possible to form a particle of foreign material on the thread.

More practical is, however, the secondary measure proposed according to the invention in which a liquid is used to increase the mass of the thread. Of course, water being a cheap raw material comes first to be considered as such a liquid.

Since the Water is applied only on a restricted portion of the thread the fabric will not be rendered wet appreciably. When, moreover, the weft threads are made a little longer than the width of the fabric and the drop of water is applied on the leading end of the thread protruding beyond the fabric width after the weft is made, these wet protruding ends are normally cut so that a dry fabric is obtained. In cases in which the above solution cannot be applied it is possible to substitute a drop of a volatile liquid, such as ether, for the water drop being used for locally increasing the mass of the thread.

A further elaborating of this idea leads to another measure suitable to realise the inventive principle, viz in that a condensable or sublimable compound is caused to be deposited on the thread.

This compound may be a liquid absorbed by a thread after condensation of a vapour, or a solid being deposited on the thread after sublimation of a vapour or liquid. Examples of such compounds are water, liquefied air, sodium and solid C0 The thread acts as a carrier or substrate of condensation or absorption nuclei. It will be obvious that the rawer the fibre is, the greater is the number of condensation or absorption nuclei, so that the condensation or absorption is greatly facilitated.

In the preceding paragraphs it has been taken for granted that air is used as the driving fluid being operative during a fraction of the time since thus far it is the most common driving fluid. In fact the only difference of the inventive method over methods of the prior art for launching a thread is just that the thread is locally made heavier. In the applications with which the method according to the invention is concerned, it is of great importance that the projection of the thread takes place with very high speeds. A further increase of speed can be obtained by enlarging the mass of the driving fluid. Due to the increase of mass both of the driving fluid and the thread, the collision phenomena will take place still more intensively resulting in a quicker displacement of the thread.

correspondingly the velocity imparted to the thread can considerably be increased according to another feature of the invention by applying as the proper driving fluid a fluid being heavier than air under normal circumstances. This fluid may be injected as vapour, as liquid or as solid and, as the case may be, may be mixed with air or another inert gas, the liquid or solid being sprayed as a mist of fine particles.

This efficiency can be increased according to a particular measure of the invention by applying as proper driving fluid the same compound being used for enlarging the mass of the thread. The term the same compound is meant to include not only a compound acting both as driving fluid and as mass enlarging means and that occurs in one single aggregation state, but also one that occurs simultaneously in different aggregation states. In this latter case the driving fluid occurs in one aggregation state and the mass enlarging means in another one, of the compound concerned. It is then possible to make use of air or even substances lighter than air. Examples of such binary systems falling under the above definition are: Water-water, steam-water, air-liquid air, ether vapour-ether liquid. To prevent in the case of the binary water-water system the fabric from being made completely wet, a water phobic compound such as a volatile oil is applied on the thread with the exception of the portion to be made heavier, before projecting on the thread the water jet acting as a driving fluid.

In case the driving fluid simultaneously acting as mass enlarging means does not adhere or not easily adhere to the thread portion concerned resort may be made apart from the above mentioned purely physical processes to processes in which the adherence between the particle of the propelling fluids and the thread is established in a chemical, galvanic, electrostatic magnetic or the like manner. In this way one compound suffices for enlarging the mass of the thread in a physical, chemical or electrical way, acting at the same time as propelling fluid.

When applying in accordance with another feature of the invention as such binary system a compound able to condense or sublime which is introduced in another than the vapour phase in the proximity of the thread and is heated for converting the compound into an expansive vapour, this expansion will further increase the velocity of the thread. Heating can take place by means of heated air or gas or a heated air nozzle or by means of an electric filament or with high frequency alternating current or through a lase beam, just to mention some examples.

It is recommended to ensure that the expansion will take place that warmth is extracted from the ambience and hence from the thread permitting a good condensation or sublimation of the vapour on the fibre. Due to the fact that these physical processes, namely heating, evaporating, expansion, cooling and condensation take place subsequently and nearly simultaneously, a good energy transfer is assured so that relatively little energy is to be added to the vapour-liquid system.

From the foregoing it will be obvious that in the various embodiments of this invention water among other suitable liquid or condensable or sublimable compounds is to be preferred for various reasons because of its cheapness, its enormous ratio of expansion and its capacity of being absorbed excellently by all kinds of fibres. Certain fibres however, the so called hydrophobic fibres, absorb Water to a lesser extent and for such fibres other substrates are to be considered, depending on factors already mentioned, namely coefficient of friction (roughness) of the fibre, density of the medium, and relative velocity of the medium in respect of the thread.

In a practical embodiment Water acting as the proper propelling agent is sprayed under high pressure and the short lasting jet is so directed that it only hits a small portion of the thread to be projected. Though the use of water as driving fluid already causes an enlargement of the mass of the driving fluid, absorption of water droplets in the thread also occurs, the fibres acting as absorption nuclei, resulting in a local enlargement of the mass of the thread.

These effects interact and cause an intensifying of the collision and friction phenomena.

The great advantage of the use of Water instead of air may appear from the following data derived from practice.

In another practical embodiment water is suddenly converted into steam resulting in a very expansive driving fluid of which the mass is greater than air. Since this confined steam jet condenses on the fibres acting as condensation nuclei, the mass of the thread is again locally enlarged, so that here also two effects may be observed mutually fortifying each other.

Generally the evaporation of a single drop sufiices for creating a volume, which is enlarged by a factor of 1000 so that the thread is projected super-quickly whilst the thread wet through condensation can be curled or, reversely, be straightened in an eflicient Way.

Apart from the above measure aiming at increasing the mass of both the thread and the driving fluid, the invention also provides some measures relating to the support of the thread during its transport by the driving fluid. In a conventional method air is used to that end, but not in combination with a thread having locally been made heavier.

In the method according to the invention such combination is used in that apart from the driving fluid use is made of still another fluid destined to transport the thread whilst supporting it and being operative during the remainder of the time necessary for displacing the thread over its full length. Suitable transporting fluids are air, steam or water, in the latter case care being taken of ensuring that the greater part of the thread has been rendered waterphobic.

Efficiency can the obtained in that in accordance with a further feature of the invention as transport fluid the same fluid is used as that used for driving the thread.

A device for carrying out the method according to the invention in which a thread is launched by means of a confined jet of a pressurized fluid and provided with a jet nozzle, is characterized by a space containing a means for enlarging the mass of the thread and having a passage for conducting the mass enlarging means to part of the thread being presented to the nozzle, means being provided to inject the mass enlarging means only during a short period of time.

The device is further characterized in that the passage forms part of the jet nozzle. In this case the mass enlarging means acts simultaneously as driving fluid.

Moreover in the device according to the invention the jet nozzle may be provided With an additional jet nozzle one nozzle serving for supplying the driving fluid and the other one for supplying the mass enlarging means.

Means for depositing the mass enlarging compound may be of galvanic, electro-static, magnetic or the like nature.

In a particular embodiment the mass enlarging means can be applied on the thread in a mechanical way. The

device is further characterized by means for heating a volatile compound serving as a driving fluid.

The invention will now be described with reference to the accompanying drawing in which FIGS. lillustrate very diagrammatically a thread and its ambience, a gaseous (light) fluid being denoted in dashed lines and a liquid (heavy) fluid in full lines.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 illustrate conventional methods;

FIGS. 3-5 serve as illustration of the method according to the invention;

FIG. 6 shows a device for carrying out the method according to the invention.

In FIG. 1 a thread 1 is shown being driven and wholly enclosed by a water jet indicated by full lines 2. Thus in this known method the whole thread becomes wet and the water not only serves for increasing the mass of the thread thereby preventing the thread structure from being disturbed or even destroyed by the force of the water jet, but also as a driving fluid and a transporting fluid.

FIG. 2 illustrates another method now in use. The thread 1 is wholly enclosed by a gaseous fluid (air) indicated with dashed lines 3 and serving as driving fluid and also as transporting fluid. However there is no question of an increase in mass of the thread nor of the fluid.

In FIGS. 3-5 the local increase in mass of the thread is diagrammatically indicated with line section 4. As driving fluid use is made of a short lasting liquid jet 2. In FIG. 3 is also indicated with reference number 3 a gaseous transporting fluid, whilst in FIG. 4 the driving fluid 2 is followed by a transporting fluid 5 progressively passing over from a liquid fluid 6 through an admixture of liquid-j-gaseous fluid 7 into a gaseous fluid 8. Such a transporting fluid is lacking completely in FIG. 5.

In FIG. 6 a device is represented for carrying out the method according to the invention. The thread 1 is located in a cavity 11 of a core 12 of a jet nozzle generally indicated by reference numeral 10, slidably arranged in a rigidly mounted housing 13, of which the mouth 14 ends near the mouth 15 of the core 12. Between the mouth 14 and the mouth 15 a ring-shaped chamber 16 is provided which narrows into a ring-shaped gap 17. The ringshaped chamber 16 contains the driving fluid which for a very short time is expulsed under pressure through the ring-shaped gap 17, in front of the cavity 11. The faces 18, 19 defining the ring-shaped gap 17 are inclined such that a confined driving jet leaves the ring-shaped gap 17 and impinges upon the thread 1 on a very restricted part thereof thereby increasing the mass of the thread locally.

Thus the compound contained in the ring-shaped chamber 16 serves both as driving fluid and as a compound for increasing the mass of the thread.

When the pressure within the ring-shaped chamber 16 is normal, the ring-shaped gap '17 is closed. Through a bore 21 ending in the ring-shaped chamber 16 a pressure can be exerted on the liquid contained in the chamber 16 such that the core 12, as seen in FIG. 6, is moved to the left against the pressure of a spring 22. This spring is enclosed in an axial sense between a ring-shaped collar 23 provided on the outer circumference of the core 12 and an externally threaded bushing 24 through which the core 12 can be slid. The bushing 24 is threaded into the internally threaded end portion 25 of the housing 13. As the core 12 moves to the left, the tension of the spring 22 is increased which tension after the pressure on the liquid in the ring-shaped chamber 16 has dropped, is transferred with a certain delay to the collar 23 and causes this latter to return to the right. In this way the core itself is also moved back to the right and the ringshaped gap 17 is closed again.

If desired a heating filament 26 can be provided on the outer circumference at the end of the core 12 near the mouth 15 so that the liquid contained in the ringshaped chamber 16 can be ejected as a vapour and the driving fluid can pass through the ring-shaped gap 17 as an expansive vapour. To ensure that part of this vapour is condensed or sublimed on the thread to in crease the mass, a cap 27 with mix-ing tube 270: is provided at the leading end of the housing 13, the axial bore 28 of the tube being in registry with the cavity 11 in the core 12. A bore 29 permits a cooling gas to enter into the bore 28 of the mixing tube 27w causing the expansive vapour to be deposited onto the thread. A particular effect is obtained herewith in that the expansive vapour is jacketed by the cooling gas facilitating the condensation or sublimation of the vapour on the thread, whilst preventing the vapour from being deposited on the inner wall of the bore 28 which would be clogged otherwise.

At the entrance (left end) of the cavity 11 air can be admitted as a transporting (supporting) fluid. Conduits can be connected to the bores 21 and 29 said conduits being coupled to a controlling means for establishing the moment and the duration of and the mutual delays between the injection of the driving fluid and that of the cooling means. Instead of a spring the reciprocal movement of the core 12 and thus the opening and closing of the ring-shaped gap 17 can be obtained by means of a cam mechanism, and to allow the coupling of said mechanism to the core, a ring-shaped recess 30 is provided on the core 12.

I claim:

1. A method of projecting a thread under the influence of a confined jet of pressurized fluid, comprising the step of increasing the weight of a local portion of the thread, wherein the improvement comprises the steps of (a) discharging a high velocity driving jet of fluid in driving engagement with such thread portion, the discharging of the driving jet being continued during only a fraction of the time necessary for the thread to be displaced over its full length, and ([b) subsequently continuing a separate flow of a supporting and transporting fluid, in contact with the thread during the remainder of the time necessary for displacing the thread over its full length.

2. A method according to claim 1 wherein the weight of a local portion of the thread is increased by applying a liquid thereto.

3. A method according to claim 2 wherein the liquid applied to a local portion of the thread and the driving jet of fluid consist of the same substance.

4. A method according to claim 1 wherein the weight of a local portion of the thread is increased by applying thereto a condensable or sublimable substance.

5. A method according to claim 4 wherein the driving jet of fluid and the substance applied to a local portion of the thread consist of the same substance.

6. A method according to claim 5 comprising the steps of introducing a condensable or sublimable substance in a state other than the vapor state, in proximity to the thread, and then heating to convert the substance into an expansive vapor.

7. A method according to claim 1 wherein the fluid of the driving jet is heavier than air under normal conditions.

8. A method according to claim 1 wherein the driving jet of fluid and the supporting and transporting fluid consist of the same substance.

9. Apparatus for projecting a thread under the influence of a confined jet of pressurized fluid, comprising a passage for conducting a thread and a transporting fluid for the thread, wherein the improvement comprises an annular nozzle which surrounds the end of the passage and is provided with a core which normally closes the annular nozzle but is axially displaceable for discharging a high velocity annular jet of fluid in driving engagement with a thread that extends out of the end of the passage.

10. Apparatus according to claim 9 wherein the passage for conducting a thread and a transporting fluid for the thread extends through the axially displaceable core.

11. Apparatus according to claim 9, comprising means for heating the interior of the annular nozzle to produce a vapor to be discharged as a high velocity annular jet upon displacement of the core.

12. Apparatus according to claim 11, comprising a tubular jacket extending beyond the end of the passage and a conduit for introducing a cooling gas into the jacket, around a thread extending out of the end of the 8 passage, to cause vapor discharged from the annular nozzle in engagement with the thread to condense upon the thread.

References Cited 5 UNITED STATES PATENTS 3,180,368 4/ 1965 Kobayashi. 3,367,373 2/ 1968 Fransen. 3,394,740 7/1968 White.

10 HENRY S. JAUDON, Primary Examiner 

